// In production, we register a service worker to serve assets from local cache.

// This lets the app load faster on subsequent visits in production, and gives
// it offline capabilities. However, it also means that developers (and users)
// will only see deployed updates on the "N+1" visit to a page, since previously
// cached resources are updated in the background.

// To learn more about the benefits of this model, read https://goo.gl/KwvDNy.
// This link also includes instructions on opting out of this behavior.

export default function register() {
	if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) {

		window.addEventListener('load', () => {
			const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`

			navigator.serviceWorker.register(swUrl).then(registration => {

				registration.onupdatefound = () => {
					const installingWorker = registration.installing
					installingWorker.onstatechange = () => {
						if (installingWorker.state === 'installed') {
							if (navigator.serviceWorker.controller) {
							  // At this point, the old content will have been purged and
							  // the fresh content will have been added to the cache.
							  // It's the perfect time to display a "New content is
							  // available; please refresh." message in your web app.
								console.log('New content is available; please refresh.')
							} else {
							  // At this point, everything has been precached.
							  // It's the perfect time to display a
							  // "Content is cached for offline use." message.
								console.log('Content is cached for offline use.')
							}
						}
					}
				}

			}).catch(error => {
				console.error('Error during service worker registration:', error)
			})
		})

	}
}

export function unregister() {
	if ('serviceWorker' in navigator) {
		navigator.serviceWorker.ready.then(registration => {
			registration.unregister()
		})
	}
}
